花叶菖蒲组织培养与快繁技术试验

取花叶菖蒲的茎尖作外植体，培养于附加不同激索配比的MS培养基匕进行不定芽诱导、增殖及试管苗生根等试验，结果表明，6种配比培养基中，最适合花叶菖蒲不定芽诱导的培养基为MS＋6-BA5mg／L；增殖培养基为MS＋6-BA5Mg／L＋NAA0．5mg／L；试管苗生根诱导前在空白Ms培养基先壮苗培养一代，生根培养基为MS＋NAA0．5mg／L。试管苗不经炼苗可直接出瓶，移栽于蛭石：珍珠岩为1：1的混合基质中，成活率可达98％以上。     

蝴蝶槐的组织培养和快速繁殖技术

以蝴蝶槐的幼叶和茎尖为试材进行离体组培快繁的研究结果表明:幼叶适合于作为繁殖材料,最佳诱导产生不定芽的培养基为MS 6-BA1.0mg/L NAA0.2mg/L,增殖培养基为MS 6-BA2.0mg/L NAA0.2mg/L,生根培养基1/2MS IBA0.2mg/L ABT1.0mg/L。试管苗经适宜条件炼苗驯化后移植大田,成活率可达85%以上,而且生长良好。     

黑果枸杞组织培养快繁技术研究

以黑果枸杞1年生苗的茎段为外植体,研究不同种类植物生长调节物质对黑果枸杞组织培养各阶段产生的影响。结果表明适合嫩茎段腋芽诱导与生长的培养基为MS;愈伤组织诱导培养基为MS+6-BA 1.0mg/L+NAA 1.0mg/L;愈伤组织诱导分化培养基为MS+6-BA 0.2mg/L;增殖培养基为MS+6BA0.1mg/L+NAA0.2mg/L;生根培养基为MS+6-BA 0.4mg/L+NAA 0.2mg/L;诱导生根的组培苗在实验室内打开瓶口炼苗7d,在温室内移栽到穴盘或合适的容器中,容器中的基质为森林土、河沙及蛭石,其比例为2∶1∶1。     

印楝快繁技术的研究

试验以印楝实生苗的嫩枝为材料,对印楝的初代培养、丛生芽诱导和生根、再生植株炼苗等进行系统研究,通过单因素和正交试验筛选出各阶段的最适培养条件:(1)初代培养基为MS 6-BA 0.5 mg/L NAA 0.05 mg/L 蔗糖30 g/L;(2)丛生芽诱导培养基为MS改 6-BA 0.4~1.0 mg/L KT 0.5~1.5 mg/L NAA 0.05~0.2 mg/L 蔗糖30 g/L;(3)生根培养基为1/2 MS IBA 0.3 mg/L PG 3μmol/L 糖20 g/L。     

蓝花楹组培技术研究

以蓝花楹实生苗茎尖作为外植体的组培技术研究结果表明,其组培中的启动培养基宜为MS 6-BA1.0 mg/L NAA0.2 mg/L;增殖培养基宜为MS 6-BA2.0 mg/L NAA0.4 mg/L或MS 6-BA2.0 mg/L NAA0.5 mg/L;生根培养基宜为1/2 MS NAA0.5 mg/L.其试管苗适宜的移栽基质为营养土 蛭石(比例1:1),移栽成活率为55.10 %.有利于其试管苗增殖的光照条件为3 000 lx.继代次数对其试管苗的增殖和生根均有影响,而适宜转向生根培养的继代数最少为9代.     

胡杨组培快繁技术研究

利用胡杨花序轴为外植体的组织培养技术,选出最适合胡杨花序轴愈伤化的培养基为B5+6-BA1mg/L+NAA0.5mg/L,诱导率达98.7%;愈伤增殖培养基较适宜的为B5+6-BA1mg/L+NAA1.25mg/L和MS+6-BA1mg/L+NAA0.5mg/L;芽分化培养基中较适宜的是MS+6-BA0.5mg/L+NAA0.2mg/L和LS+6-BA1mg/L+NAA0.5mg/L。壮苗培养基以1/2MS+6-BA0.2mg/L+NAA0.5mg/L为宜,此培养基得到的苗叶色浓绿,较粗壮。而以1/2MS为基本培养基,添加1.5～2.0mg/LIBA有利于胡杨组培苗的生根。     

四倍体刺槐组织培养研究

四倍体刺槐是生态价值和经济价值兼顾的多用途优良树种。通过腋芽诱导、增殖、壮苗及生根培养、炼苗移栽试验,以筛选出四倍体刺槐组培快繁的最适培养基。结果表明,4月至5月是四倍体刺槐的外植体采集最佳时机;增殖培养以MS+6-BA(0.3~0.7mg/L)+NAA(0.05~0.2mg/L)为宜,其有效增殖率可达3~5倍;在培养基MS+6-BA(0.1~0.2mg/L)+KT 0.05mg/L+NAA(0.01~0.05mg/L)+IBA(0.01~0.05mg/L)中,壮苗效果较好;1/2 MS+NAA 0.05mg/L+IBA 0.05mg/L+ABT 0.1mg/L为较适合的生根培养基;春季是组培苗炼苗的最佳季节,60天炼苗成活率可达60%左右。     

不同植物激素用量对菊叶薯蓣组织培养的影响

以菊叶薯蓣幼嫩茎段为外值体进行不同植物激素用量的组培试验结果:外植体诱导培养基MS+6-BA1.0～2.0mg/L+NAA0.1～0.2mg/L,萌动率92.31%～95.00%;继代增殖培养基MS+6-BA0.5mg/L+NAA0.1mg/L,成苗率87.27%,增殖系数4.55倍;生根培养基1/2MS+NAA0.5mg/L+IBA1.0mg/L,生根率90.95%,形成完整植株58.20%;以第一节位茎段培养生根率和形成完整植株率最高,分别是92.35%和81.91%。瓶苗移栽炼苗时,采用两种处理方法炼苗,以第二种处理炼苗法的移苗成活率最高,达80%以上。     

欧洲水仙鳞片组织培养与快速繁殖

以欧洲水仙‘Dutch Master’为研究材料,通过对鳞片取材部位、培养光照、激素配比以及组培苗移栽基质的研究发现,欧洲水仙初代培养的较适外植体为内层鳞片下部,合适光照度为1 000 lx。愈伤组织诱导培养基为MS+6-BA 2.0 mg/L+2,4-D 0.3 mg/L+蔗糖30 g/L,小鳞茎的诱导分化培养基为MS+6-BA 2.0 mg/L+NAA 0.2mg/L+蔗糖30 g/L,小鳞茎继代增殖培养基为MS+6-BA 1.5 mg/L+NAA 0.3 mg/L+蔗糖30 g/L,生根培养基为1/2MS+6-BA 0.3 mg/L+NAA 0.5 mg/L+蔗糖20 g/L。炼苗移栽基质配比为V(蛭石)∶V(泥炭土)∶V(园土)=1∶1∶2。     

宜兴百合组培快繁体系的建立

以宜兴百合鳞片为外植体进行试管培养,经试验筛选出各培养阶段适宜的培养基为:(1)小鳞茎诱导,MS 6-BA 0.5mg/L NAA 1mg/L KT 0.2mg/L;(2)分化及继代,MS 6-BA 0.2mg/L NAA 0.5mg/L;(3)生根,MS PP3331 mg/L NAA 0.1 mg/L。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.